The recent discovery of crystalline pentazolates marks a major advance in polynitrogen science and raises prospects of making the long-touted potent propellant N$_5$$^{+}\(N\)_5$$^{-}\( salt. ...However, despite the synthesis of cyclo-N\)_5$$^{-}\( anion in pentazolates, counter cation cyclo-N\)_5$$^{+}\( remains elusive due to the strong oxidizing power of pentazole ion; moreover, pure N\)_5$$^{+}\(N\)_5$$^{-}\( salt is known to be unstable. Here, we devise a new strategy for making rare cyclo-N\)_5$$^{+}\( cation and assembling the long-sought N\)_5$$^{+}\(N\)_5$$^{-}\( salt in tailored ionic compounds, wherein the negative/positive host ions act as oxidizing/reducing agents to form cyclo-N\)_5$$^{+}\(/N\)_5$$^{-}\( species. This strategy is implemented via an advanced computational crystal structure search, which identifies XN\)_5\(N\)_5\(F (X = Li, Na, K) compounds that stabilize at high pressures and remain viable at ambient pressure-temperature conditions based on \textit{ab initio} molecular dynamics simulations. This finding opens an avenue for creating and stabilizing N\)_5$$^{+}\(N\)_5$$^{-}\( salt assembly in ionic compounds, where cyclo-N\)_5$ species are oxidized/reduced via co-matching with host ions of high/low electronegativity. The present results demonstrate novel polynitrogen chemistry, and these findings offer new insights and prospects in the design and synthesis of diverse chemical species that exhibit unusual charge states, bonding structures, and superior functionality.
Due to imbalanced distributed and restricted medical resources, reliable analysis for medical images is hard to come by, and it is impractical to only rely on human beings to do all the analysis, ...which is time-consuming and not economic. Application of computer vision techniques in such fields emerges as the situation requires. In this paper, we use deep learning segmentation algorithm to segment the optic disc and the cup from each other and from the rest of the ophthalmoscopy photographs. For a better performance, we change the loss function and crop as a way of data augmentation. The segmentation results can be used to calculate the cup-to-disc ratio (CDR), which is further used to diagnose glaucoma. Challenges such as over-fitting, biased dataset, and poor generalization of the model exist in front of us. We illustrate our model and associated methods dealing with these challenges.
In this paper, we aim to automatically detect glaucoma via deep learning. To do that, we need to calculate the cup-to-disc ratio (CDR) on fine segmented retina images. To get precise segmentation, we ...implemented SegNet together with adversarial discriminative domain adaptation (ADDA), the former is a famous artificial neural network with encoder-decoder architecture used in image segmentation area and the latter is a transfer learning method for domain adaptation. We are the first to combine them together to detect glaucoma on test dataset which have different brightness from our training dataset. We thoroughly evaluated the proposed method with various loss functions, normal cross entropy loss, weighted cross entropy loss and dice coefficient loss included. And we show that dice loss is the best for this task. Last but not least, our experiments on transfer learning have shown that our ADDA method reduces the mean square error (MSE) between the CDR of our segmentation and annotations greatly.
The rapid development of artificial intelligence (AI) is driving significant changes in the field of atomic modeling, simulation, and design. AI-based potential energy models have been successfully ...used to perform large-scale and long-time simulations with the accuracy of ab initio electronic structure methods. However, the model generation process still hinders applications at scale. We envision that the next stage would be a model-centric ecosystem, in which a large atomic model (LAM), pre-trained with as many atomic datasets as possible and can be efficiently fine-tuned and distilled to downstream tasks, would serve the new infrastructure of the field of molecular modeling. We propose DPA-2, a novel architecture for a LAM, and develop a comprehensive pipeline for model fine-tuning, distillation, and application, associated with automatic workflows. We show that DPA-2 can accurately represent a diverse range of chemical systems and materials, enabling high-quality simulations and predictions with significantly reduced efforts compared to traditional methods. Our approach paves the way for a universal large atomic model that can be widely applied in molecular and material simulation research, opening new opportunities for scientific discoveries and industrial applications.
The Forbush Decrease (FD) represents the rapid decrease of the intensities of charged particles accompanied with the coronal mass ejections (CMEs) or high-speed streams from coronal holes. It has ...been mainly explored with ground-based neutron monitors network which indirectly measure the integrated intensities of all species of cosmic rays by counting secondary neutrons produced from interaction between atmosphere atoms and cosmic rays. The space-based experiments can resolve the species of particles but the energy ranges are limited by the relative small acceptances except for the most abundant particles like protons and helium. Therefore, the FD of cosmic ray electrons and positrons have just been investigated by the PAMELA experiment in the low energy range (\(<5\) GeV) with limited statistics. In this paper, we study the FD event occurred in September, 2017, with the electron and positron data recorded by the Dark Matter Particle Explorer. The evolution of the FDs from 2 GeV to 20 GeV with a time resolution of 6 hours are given. We observe two solar energetic particle events in the time profile of the intensity of cosmic rays, the earlier and weak one has not been shown in the neutron monitor data. Furthermore, both the amplitude and recovery time of fluxes of electrons and positrons show clear energy-dependence, which is important in probing the disturbances of the interplanetary environment by the coronal mass ejections.
: Magnesioferrite, a rare metasomatic mineral, was discovered for the first time in China from the Qinlou Au (Fe, Cu) magnesian skarn deposit, Sanpu, Huaibei, Auhui Province, and the Mulonggou Fe ...(Mo, Cu) magnesian skarn deposit, Luonan County, Shaanxi Province. In this paper, the geological setting, mineral associations, chemical composition, some physical properties, X‐ray powder diffraction data and infrared spectroscopy of magnesioferrite and magnesiomagnetite are discussed. Magnesioferrite contains 17.66%–13.48% of MgO. Its main associated minerals are clinohumite, chondrodite, serpentine, calcite and magnesiomagnetite. The density of magnesioferrite is 4.537–4.720, reflectances in percent are: 17.8–18.1, hardness is 838–900 kg/mm2, and the cell parameter ao = 8.371–8.379 Å. A systematic study of the magnesioferrite‐magnesiomagnetite‐magnetite series suggests that along with the increase of magnesioferrite molecules in the mineral, the density, reflectances and cell parameters decrease correspondingly, the hardness heightens, and the infrared absorption spectral band becomes wider. The authors consider that magnesioferrite is a product of contact metasomatism between hypabyssal intermediate‐acid intrusions and dolomitic marble. It was formed in shallow exocontact zones under relatively oxidized conditions.
As the traditional GEAR protocols are lack of enough topology information of the network, routing void and holes diffusion will be appeared. This paper puts forward advanced GEAHAR routing mechanism, ...which has taken the information of second-hop nodes into consideration, consequently reducing the probabilities of the occurrence of routing void. Moreover, the article discusses the relationship between the power of wireless transmission and the communication radius, then proposes the AGEAR and AGEAHAR routing mechanism, which will automatically adjust the power of transmission according to the communication distance. Based on the above discussion, the article draws the conclusion that the smaller number of hops does not indicate the lower energy consumption, and proposes that taking the price of communication into account at the time the node choosing its next hop, which further reduce the energy consumption of the entire network and, as a consequence, prolong the life of the network.
Modeling of price effects for the adoption of LCD TV Bi-Huei Tsai; Yiming Li; Lee, G.-H.
PICMET '09 - 2009 Portland International Conference on Management of Engineering & Technology,
2009-Aug.
Conference Proceeding
This paper focuses on the global LCD TV panel shipments from the first quarter of 2002 to the second quarter of 2008. The aims of this study are to incorporate realistic price data to systematically ...inquiry effects of innovation, imitation, price elasticity and potential market size in global LCD TV panel diffusions. Two different models, the Bass model and the modified one are thus numerically solved and optimized to estimate the market dynamics of LCD TVs, where the results among the models and collected data in the past decade are compared and validated for the best accuracy. The results of this study imply that the positive internal influence is mainly through consumers' word of mouth. Previous LCD TV adopters persuade the potential ones to imitate the former in the TV transaction decisions. Particularly, LCD TV price reduction stimulates the successive LCD TV consumers, which indicates the significance of the modeled price effect in LCD TV adoptions. Empirical results for the past decade data shows that the 32-inch LCD TV remains the mainstream due to a largest size of potential market. In addition, the model with considering the effect of price performs better in fitness than that of the conventional one and the prediction of modified model is superior to that of the Bass model for 32-inch LCD TVs.
目的:筛查弱精子症患者精子中差异表达蛋白质,进行生物信息学分析,阐明重要的生物学过程、分子功能及相关的代谢通路,为进一步开展机制研究提供方向与思路.方法:分别收集正常人和弱精子症患者各30例的精子样本,利用串联质谱标签技术(Tandem Mass ...Tag,TMT)筛查和鉴定弱精子症患者精子中的差异蛋白,并对其进行GO和KEGG分析.结果:以P＜0.05,且表达倍数≥1.2或≤0.833为标准,与正常人组精子相比表达有差异的蛋白共1 020种,上调蛋白606种,下调蛋白414种. GO分析结果显示上述差异表达蛋白主要参与mRNA分解过程、终止翻译过程,在核糖体和部分胞质均有分布,且具有结合功能、受体活性功能等;差异蛋白参与的KEGG信号通路为代谢通路、腺苷酸活化蛋白激酶(AMPK)信号通路和氧化磷酸化通路等257条通路.结论:弱精子症患者差异表达蛋白质涉及到复杂的生物学过程、功能与通路,为进一步开展弱精子症发病机制的研究提供了重要的方向与生物信息.
